The life cycle of the hair includes growing, transitional and resting stages.

The growth stage

The growth stage is called 'anagen' and in this stage a follicle reforms and the matrix divides to create a new hair. This process will vary in time depending on the location and function of the hair. This is the only stage of hair growth where laser hair removal or electrolysis will be successful.

The transitional stage

The transitional or 'catagen' stage usually lasts 1 -2 weeks. During this stage the hair separates from the base of the follicle as the dermal papilla breaks down.

The resting stage

Finally, in the resting stage or 'telogen', the follicle is no longer attached to the dermal papilla and that hair moves up the follicle and is naturally shed.

Laser hair removal and electrolysis is most effective when the hair is in the anagen stage and hence the reason as to why a number of treatments is required.